Descriptions

We define the notion of sustainable yields for ecosystem, with particular
emphasis on long-run consistency between ecological and economic conflicting
objectives. We provide a way to compute sustainable yields by means of
a viability analysis of generic ecosystem models with harvesting. We apply
our approach to a Lotka–Volterra model of the anchovy–hake couple in
the Peruvian upwelling ecosystem between the years 1971 and 1981. Our
analysis suggests that, during the anchovy collapse, the fishery could theoretically
have been viably managed to produce catches above the expected
levels while ensuring biological conservation. Control theory and viability
theory methods have allowed us to introduce ecosystem considerations, such
as multispecies and multiobjectives, and have contributed to integrate the
long term dynamics, which is generally not considered in conventional fishery
management.